What is Nucleus of an atom?
The nucleus is the central part of the atom that contains the subatomic particles: protons and neutrons.
Nucleus of an atom
The presence and the number of protons and neutrons in the nucleus of an atom define certain important characters, such as atomic number, atomic mass, and isotopic forms.
What is Atomic number?
Atomic number is the number of protons present in the nucleus of an atom. It is denoted by the
letter ‘Z’.
The atom of every element has a fixed number of protons in its nucleus. For example, any atom of oxygen always has 8 protons in its nucleus.
Oxygen atom
Why is the atomic number of an atom important?
Consider the previous example. Except oxygen, no other element has atoms with eight protons in it. This means that the number of protons in the nucleus of an atom or the atomic number is unique to that element and thus is the identity of that element.
Also, the number of electrons determines the valency and, thus, the reactive capacity of an atom. We know that in an atom, the number of electrons is equal to the number of protons. Therefore, the number of protons of an atom or its atomic number is very important.